The present invention relates to an angular velocity sensor which is capable of sensing an angular velocity acting on the sensor body to generate an electrical detection signal.
Generally, two types of angular velocity sensors are used: a gas flow type which is intended to detect a deflection of gas flow by the use of a temperature sensing element when an angular velocity acts on the sensor body, and a piezoelectric type which is intended to sense a change in resonant frequency of a pair of piezoelectric elements. Both the temperature sensing element and piezoelectric element may have varying characteristics with temperature and time causing an error in angular velocity measurement.
As a result, even with no rotational motion being applied to the sensor body an error output may be produced due to a deviation of characteristics of paired temperature sensing elements or piezoelectric elements.
In the prior art, since the offset output varies depending upon a change of the internal temperature of the angular velocity sensor, the sensor body is forcibly heated in such a way that its internal temperature detectable by the temperature sensing element may be constantly kept at the preset value.
Thus an angular velocity detection signal is compensated for a value corresponding to the offset caused at the preset temperature.
However, this technique of controlling the temperature by heating the sensor body by the use of a heater is disadvantageous as the compensation of the angular velocity detection signal can not be performed during the time interval necessary to raise the internal temperature of the sensor body to the preset value.